The German official’s trip to California to talk climate-efforts with Brown demonstrates determination of some U.S. governors, some 200 U.S. mayors, business leaders and others to keep cutting Americans’ output of climate-changing emissions from fossil fuels, Brown said.

That is despite Trump’s announcement last week that he would pull the country out of the 2015 Paris global accord. Germany and almost all the world’s other governments are still in the accord, which pledges them to curbing emissions from gasoline-powered engines and other sources of carbon.

Trump’s declaration last week prompted a series of corresponding announcements of new climate alliances and efforts nationally by state leaders and others determined to keep up U.S. efforts overall against climate change.

Brown, one of the United States’ highest-profile campaigners to cut carbon emissions, spoke a day after returning from a week of climate-change events in China.

“The United States by withdrawing under Trump has taken a back seat” on fighting climate change, Brown said.

“But that’s temporary,” the California governor said. “This current decision will not stand.”